Recently, uninhabited airborne vehicles that are called drones have been spread and used in industrial fields, for example, taking a picture from the sky and delivering packages. Although drones indicates all the uninhabited airborne vehicles, many are of multirotor types with a plurality of rotary wings as their main characteristics, which can control the direction and the altitude of the airframe and can be controlled by a communication method such as radio, Wi-Fi®, and Bluetooth®.
However, the number of the falling accidents caused by a dead battery or out of control is increasing as drones are spread. Accordingly, the safety when a drone falls is desired to be improved.
Therefore, a product to install a parachute in drones has been designed (Non-Patent Document 1).